The dryingtemperatures were found to have
a significant effect on the moisture loss rates of samples. Microwave
oven drying took shorter time to dry the product than that required
for the other drying conditions used in the assay. The drying curves
could be well fitted by the Page, Modified Page and Midilli and
Küçük models. Microwave drying yield the highest Deff values
which were approximately 50 fold higher than that of sun and oven
(50 C) drying. The value of Deff for the sun drying method was 1.12
fold higher than that for the oven drying at 50 C. Microwave ovendrying with low output power (210 W) could retain phenolics of the
product better than sun and oven drying. The changes in the
concentrations of minerals were dependent on the method and the
drying temperature. By oven drying at 70 C, the mineral content of
dried sample became higher than that of other dried samples.
Microwave oven (210 W) and sun drying revealed optimum colour
values. Oven drying at 70 C and microwave oven drying at 700 W
developed the least acceptable colour values. So, if the economics of
the process is considered, oven drying at low temperature is
generally recommended.